Weight Gain and Plasma Free Lysine of Chicks Fed an Imbalanced Amino Acid Mixture

Abstract

HILL et al. (1961) and Hill and Olsen (1963) reported a marked depression in weight gain of chicks when zein or an amino acid mixture devoid of lysine were fed as a portion of a diet containing a low level of soybean protein. The direct cause of the effect on weight gain could not be ascertained from these experiments. However, in view of reports by others (Deshpande et al., 1958; Spolter and Harper, 1961; Kumta and Harper, 1961; Fisher and Shapiro, 1961) it could be postulated that a depressed feed intake when the birds received the amino acid mixture was a major factor influencing the weight gains.The experiments to be described below were designed to test this possibility by equalizing the feed intake, both by employing a forced-feeding and a paired feeding technique. In addition, a preliminary experiment was conducted to study the possible influence on weight gain of…